Sliding doors are commonly used in residential housing both in houses, to provide access to the outdoors typically the backyard, and in apartments, to provide access to balconies. These sliding doors are typically made of tempered glass with metal or wood frames and provide a source of natural light. However, these doors are heavy and can be difficult to open especially for children, elderly people, handicapped individuals and adults when their hands are full. Accordingly it would be desirable to provide a means to open the sliding door easily.
Some commercial automatic sliding door systems are currently available such as those found in supermarkets. Such systems typically either include a sensing device or a pressure activated mat, either of which, when activated cause the door to open. The door's opening and closing mechanism and sensors combine to form an integral system wherein none of the components could operate independently. These systems are very large and would be costly to install in a home.
Some solutions have been suggested for residential sliding doors. For example U.S. Pat. No. 3,890,744 issued to Gallis on Jun. 24, 1975. The Gallis patent includes a housing which is mounted on the floor adjacent to a fixed glass door. Within the housing is an endless belt which is attached to the sliding door and is driven by an electric motor also located within the housing. Electrical limit switches act to stop the door at its open and closed positions. A solenoid is connected to the motor to tighten the belt when electric power is applied. When electric power is not applied the belt is lose and the door can be opened manually. Alternatively a locking means is suggested wherein the belt is kept taught through continuously energizing the solenoid.
Another sliding door opening system is disclosed in U.S. Pat. No. 4,893,435 issued to Shalit on Jan. 16, 1990. This system is similar to the Gallis system in that it uses an endless belt attached to the sliding door which is driven by an electrical motor. Shalit varies the Gallis system by providing the endless belt in a low profile housing and spacing the motor above and to one side of the housing adjacent the sliding doors. The belt is a toothed belt which engages a toothed sprocket. The toothed sprocket is driven by the motor. Further, Shalit provides a locking pin which engages the toothed sprocket and holds it in position. When the motor is engaged a solenoid is energised which disengages the locking pin. The locking pin can also be manually disengaged. There is a clutch between the toothed sprocket and the motor so that when the motor is not energised the door can be opened and closed manually.
Both of these are continuous loop-type systems with a multiplicity of components. Each of these components adds to the cost of manufacturing and affects the reliability of the device.
Accordingly it is desirable to provide a door opening and closing device that can easily be retro-fitted onto existing residential sliding door systems. It is desirable that such a device is easy and relatively inexpensive to manufacture. Such a device could be adapted so that a child could activate it and/or so that a dog or another pet could activate it. Further it could be adapted so that it could be activated remotely. Such a device would fulfil various needs as a convenience device. It would make sliding doors operable even when the users hands were full and it would allow a small child to operate the sliding doors. It could provide for the automatic closing of the door if so desired. As a handicap aid, it would give more independence to those in wheelchairs, those using walkers and seniors that may be too weak to operate the doors manually. As a pet door opening device it would free the pet owner from having to manually opening the door whenever the pet wants to come in or go out.